Valve control unit, particularly pilot control unit for a pressure modulator of a commercial vehicle

ABSTRACT

The invention relates to a valve control unit, particularly for a pressure modulator of a commercial vehicle. Said valve control unit ( 1 ) comprises a valve control housing ( 2 ), solenoid valves ( 4, 5, 6 ) which are provided with solenoids ( 16 ) and internal valve pieces ( 4   a,    5   a,    6   a ) inserted into the solenoids ( 16 ), and a pneumatic interface ( 14 ). The solenoids ( 16 ) are accommodated inside the valve control housing ( 2 ). Pressure sensors ( 10 ) for measuring pneumatic pressures are accommodated in or on the valve control unit, preferably on the top surface. Valve bores ( 3 ), into which the internal valve pieces ( 4   a,    5   a,    6   a ) are inserted, extend within the valve control housing ( 2 ). Air ducts ( 12 ) extend between the pneumatic interface ( 14 ), the valve bores ( 3 ), and the pressure sensors ( 10 ), inside the valve control housing ( 2 ). The solenoids ( 16 ) and pressure sensors ( 10 ) are contacted with an electrical interface ( 8 ). Advantageously, the valve control housing ( 2 ) is embodied as a single piece.

The present invention generally relates to a valve control unit, especially, a pilot control unit for a pressure modulator of a commercial vehicle.

By means of its solenoid valves, a pilot control unit activates an air-flow-boosting relay valve, which, in turn, can activate one or more ducts. For use in an electropneumatic brake system, such as, for example, an electronically regulated brake system (EBS) for trailers, wheel-brake modules having brake cylinders for the wheel brakes are activated by the relay valve.

DE 100 09 116 A1 describes a pilot control unit for a brake pressure modulator in a trailer having an electronic brake system. The solenoid valves are constructed as cartridge solenoid valves, whose valve cartridges are placed in a housing having a solenoid. First, this solenoid is introduced into the housing, and, then, the valve cartridge is inserted in an assembly direction into the housing and joined to the housing. The pilot control unit is provided with a pneumatic and an electrical interface.

DE 10 2004 035 763 A1 describes a valve control device that is preferably provided as a valve control unit for two brake ducts of an electro-pneumatic brake system. It has three valve units, each of which is designed as a valve modulator device for a brake pressure regulating circuit; in this case, an air admission valve is provided with a primary armature and a vent valve is provided with a secondary armature, the two magnet armatures having a common armature guide arrangement and a common solenoid system and being switched at different current intensities. Thus, air can be admitted to the downstream wheel module, the input pressure can be held and venting can be achieved by means of a common solenoid system.

However, such valve control units of pilot control units generally have complex structures and require a large installation space. In particular, the manufacture of a main housing and further components as well as the pneumatic passage of air through diverse air ducts, seals and possibly tubes between the various components is time-consuming and laborious. Mounting of the solenoids and pressure sensors as well as contacting with the electronics via the separate interfaces is also time-consuming and laborious.

In the case of a defect of the sensors, valves or electronics, the entire valve control unit must then be replaced.

It is an object of the present invention to provide a valve control unit, especially, for a pneumatic pressure modulator of a commercial vehicle, that is cost-effective to manufacture, has low susceptibility to malfunction, and can be installed in a small space.

This object is achieved by a valve control unit according to claim 1. The dependent claims describe preferred improvements. The claims additionally describe a pressure modulator with such a valve control unit designed as a pilot control unit.

According to embodiments of the present invention, therefore, the solenoid valves in what is preferably a one-piece housing or housing shell are formed by solenoids housed in the housing and valve cartridges introduced into valve bores, while, furthermore, the pressure sensors are mounted on a side of the housing. Preferably, the pressure sensors (micro-structured) are placed as sensor hybrids or hybrid chip arrangements directly on the top side of the housing. In this case, an electrical interface, in which the solenoids are contacted and the pressure sensors are contacted, is formed on one side of the housing, preferably, the top side of the housing. Thus, the pressure sensors can be directly contacted electrically with a circuit substrate, such as a printed circuit board, and the solenoids can be contacted directly with the circuit substrate.

The inventive valve control unit is space-saving and has low susceptibility to malfunctions, since the internal air supply lines are safe from mechanical damage or leaks. The electrical contacting or bonding via the electrical interface also has low susceptibility to malfunctions. The pressure sensors permit direct measurement of the pneumatic pressures without additional tube connections.

According to the invention, the control device is advantageously not provided directly on the valve control unit but is contacted with the valve control unit via its electrical interface; as an example, however, it may also be mounted directly on the circuit substrate.

Furthermore, the valve control device has a pneumatic interface, which is advantageously formed on one side of the housing as a labyrinth seal or as a contour for a labyrinth seal. This pneumatic interface has ports for a plurality of lines, for example, to a reservoir pressure and for various outputs.

Thus, the valve control housing can be placed with this side directly on the relay valve and pressed against it by means of a screwed connection, for example, without the need for further substantial seals. The pressure chambers of the relay valve can be extended directly, without machining or without substantial machining, to the needed pressure ports of the valve control housing, or in other words to the solenoid valves housed therein or to the pressure sensors.

Advantageously, the valve control housing is constructed and arranged such that the pressure sensors together with the electrical interface are disposed on the top side and the pneumatic interface is disposed on the opposite side, or in other words the bottom side, and the solenoid valves are oriented in horizontal direction relative thereto. Thus, air supply bores run from the pneumatic interface to the top side, just underneath the pressure sensors, and further to the bores that house the valve cartridges of the solenoid valves. These bores can be formed directly in the plastic housing, without substantial finish-machining.

As an example, the solenoids can be introduced from the top side, for which purpose there is formed a recess such as a molded pocket beginning at the top side of the valve control housing. According to one variant, therefore, the circuit substrate can be introduced from above together with already soldered solenoids or can be placed on the solenoids and contacted therewith or soldered thereto; thereafter, the circuit substrate forms the electrical interface or contains an additional plug as the electrical interface. The pressure sensors or sensor hybrids, which are also placed from above, can be contacted directly with the circuit substrate, for example by being bonded thereto. The valve internals are preferably designed as valve cartridges and can be introduced in sideways direction into the solenoids; thus, manufacture and assembly can be achieved very easily in a few process steps. The valve cartridges can be used for fixing and, if necessary, also for retaining the solenoids.

The valve control housing can be manufactured relatively simply, for example as an injection-molded part having molded pockets and completely formed bores or ducts, and can be equipped in a few process steps with the further components, or, in other words, the circuit substrate with solenoids soldered thereto, valve cartridges and pressure sensors or sensor hybrids. Thereafter, the valve control unit can be placed directly on the relay valve and pressed sealingly against it, for example, by screwed connections.

The inventive valve control unit can be used as a pilot control unit both in an electro-pneumatic brake system, or, in other words, in an electro-pneumatic brake pressure modulator for activation of the relay valves for the downstream brake ducts, and in an electro-pneumatic level-regulating system with air bellows for level regulation or traction regulation.

An exemplary embodiment of the invention will be explained in greater detail hereinafter on the basis of the attached drawings, wherein:

FIG. 1 is a side view of an inventive valve control unit as a pilot control unit with connecting cable and plug;

FIG. 2 is an overhead view of the pilot control unit from FIG. 1;

FIG. 3 shows the pilot control unit from FIGS. 1 and 2 in perspective cross section through a housed valve, without cutaway view of the valve cartridge;

FIG. 4 shows a horizontal section through all valves of the pilot control unit; and

FIG. 5 shows how the pilot control unit is installed in the complete pressure modulator.

A pilot control unit 1 is provided with a pilot control housing 2, preferably made of plastic, in which there are housed solenoid valves 4, 5, 6. Bores 3, into which valve cartridges 4 a, 5 a, 6 a are introduced, run in transverse direction through pilot control housing 2. In the interior of pilot control housing 2 there is provided a free space, formed as a molded pocket 9, for solenoids 16, into which valve cartridges 4 a, 5 a, 6 a are introduced. A circuit substrate 7, for example, a printed circuit board 7 having an electrical interface 8, such as, for example, a plug 8, is mounted on top side 2 a of pilot control housing 2. Solenoids 16 are fastened directly to printed circuit board 7 at contacts M1+, M1−, M2+, M2−, M3+, M3−. According to FIGS. 1 and 2, a ribbon cable can be connected to electrical interface 8.

On top side 2 a there are further mounted pressure sensors 10, for example in the form of micro-structured chip sensors (DIE sensors) having a sensor chip on a chip substrate, such as a ceramic hybrid. On bottom side 2 b of pilot control housing 2 there is formed a pneumatic interface 14 of pilot control unit 1, from which interface air ducts 12 run to pressure sensors 10 and to solenoid valves 4, 5, 6. Pneumatic interface 14 is simply pressed against relay valve 18 to form a sealing labyrinth; for this purpose, seals 31 are provided at pneumatic interface 14.

Pressure sensors 10 can be fastened directly, that is, without chip substrate, to top side 2 a of pilot control housing 2 and contacted with printed circuit board 7 by bond connections.

Depending on the application, different valves can be used as the solenoid valves, for example a 3/2-way valve as redundancy valve 5, which, in its de-energized condition, (redundancy case) permits pneumatic gating control of the brake-force transducer of the driver, and, in its energized condition, permits electro-pneumatic EBS control.

Furthermore, in a simple case, there can be provided a 2/2-way valve as air admission valve 4 and a further 2/2-way valve as vent valve 6. According to a preferred embodiment, two-stage solenoid valves 4 and 6 of the type known in principle from DE 10 2004 035 763 A1 are provided for this purpose. Thus, each solenoid valve 4, 6, respectively, has a 2/2-way primary valve on its primary side and a 3/2-way valve on its secondary side, the primary armature and secondary armature being guided in a common armature guide tube and controlled by a common solenoid system having two current levels. In the de-energized condition, the primary valve is then open and the secondary valve is in its air admission position, thus, permitting admission of air or supply of control pressure. At a first, lower current intensity, the primary valve closes without change of the secondary valve, so that the pressure is held in the downstream pneumatic cylinder; at the second, higher current intensity, the secondary valve is displaced (while the primary valve remains shut off without change) such that venting can take place via the secondary valve.

Valves 4, 5, 6 are in communication with pneumatic interface 14 via air ducts 12 formed internally in pilot control housing 2.

Advantageously, therefore, no electrical control device is provided on this pilot control unit 1. Control is exercised via electrical interface 8.

Alternatively, however, printed circuit board 7 can also be equipped with the control device, such as a microprocessor and/or further electronic components of a regulator.

FIG. 5 shows how pilot control unit 1 together with its pneumatic interface 14 formed as a sealing labyrinth is introduced downward onto air-flow-boosting relay valve 18. An electrical component 20 is placed on top of pilot valve unit 1 and contacted with electrical interface 8, thus, forming pressure modulator 24. 

1. A valve control unit, especially a for a pressure modulator of a commercial vehicle, wherein the valve control unit (1) is provided with: a valve control housing (2), solenoid valves (4, 5, 6), solenoids (16) and valve internals (4 a, 5 a, 6 a) inserted into the solenoids (16), and a pneumatic interface (14), wherein the solenoids (16) are housed in the valve control housing (2), wherein valve bores (3) in which the valve internals (4 a, 5 a, 6 a) are inserted run in the valve control housing (2), characterized in that: pressure sensors (10) for measuring pneumatic pressures are housed in or on the valve control unit, air ducts (12) run in the valve control housing (2) between the pneumatic interface (14), the valve bores (3) and the pressure sensors (10), and the solenoids (16) and pressure sensors (10) are contacted with an electrical interface (8).
 2. A valve control unit according to claim 1, characterized in that the valve control housing (2) is formed in one piece.
 3. A valve control unit according to claim 1 or 2, characterized in that at least two solenoid valves (4, 5, 6) are formed as two-stage solenoid valves with two armatures housed in a common solenoid system, wherein the solenoid system can be operated when de-energized and also when energized with a first lower current intensity and a second higher current intensity.
 4. A valve control unit according to one of the preceding claims, characterized in that the pressure sensors (10), in the form of sensor chips, such as sensor hybrids, are mounted and contacted on a top side (2 a) of the valve control housing (2).
 5. A valve control unit according to claim 4, characterized in that a circuit substrate (7), with which the pressure sensors (10) and the solenoids (16) as well as the electrical interface (8) are contacted, is mounted on the top side (2 a).
 6. A valve control unit according to claim 5, characterized in that the electrical interface (8) is formed only on the top side (2 a) of the valve control housing (2), for example with or on a printed circuit board (7) and/or a flexible film and/or a stamped grid.
 7. A valve control unit according to claim 5 or 6, characterized in that the circuit substrate (7) is equipped with further components, especially with a control device for electrical control of the solenoid valves and/or with components of a regulating electronic unit.
 8. A valve control unit according to one of claims 1 to 6, characterized in that it is free of any electronic control device and, via its electrical interface (8), is connected to an external electronic control device.
 9. A valve control unit according to one of claims 5 to 8, characterized in that the pneumatic interface (14) is disposed on the bottom side (2 b) of the valve control housing (2), opposite the top side (2 a), and air ducts (12) run in the valve control housing (2) from the pneumatic interface (14) to the pressure sensors (10).
 10. A valve control unit according to one of the preceding claims, characterized in that the pneumatic interface (14) contains or forms a labyrinth seal.
 11. A valve control unit according to one of the preceding claims, characterized in that the pneumatic interface (14) is provided with a plurality of pneumatic connections between pneumatic lines.
 12. A valve control unit according to one of the preceding claims, characterized in that the solenoids (16) are disposed in a middle free space (9) of the valve control housing (2), such as a molded pocket (9), through which there run the valve bores (3) containing the valve internals (4 a, 5 a, 6 a) inserted therein.
 13. A valve control unit according to claim 12, characterized in that the valve internals of a solenoid valve are each formed as a valve cartridge (4 a, 5 a, 6 a) that can be inserted in one piece.
 14. A valve control unit according to claim 13, characterized in that the inserted valve cartridges (4 a, 5 a, 6 a) fix the solenoids (16) introduced into the free space (9).
 15. A valve control unit according to one of the preceding claims, characterized in that the pneumatic interface (14) is placed on an air-flow-boosting valve (18) and is fastened sealingly by a pressing force developed, for example, via fastening screws.
 16. A valve control unit according to one of the preceding claims, characterized in that, as solenoid valves (4, 5, 6), there are provided at least: a redundancy valve (5) for changing over between pneumatic redundancy operation and electropneumatic control, and/or two solenoid valves (4, 6) for air admission and venting.
 17. A valve control unit according to one of the preceding claims, characterized in that it is a brake pressure pilot control unit for the electropneumatic brake system of a commercial vehicle or a pilot control unit of a pneumatic level regulator or traction regulator of a commercial vehicle.
 18. A valve control unit according to one of the preceding claims, characterized in that the one-piece valve control housing (2) is formed from plastic, for example by manufacture in an injection-molding process.
 19. A pressure modulator (24) having a valve control unit designed as a pilot control unit (1) according to one of the preceding claims, a relay valve (18) placed sealingly on the pneumatic interface (14) by application of a pressing force, and an electronic device (20) containing a control device, wherein the electronic unit (20) is contacted with the electrical interface (8) of the pilot control unit (1). 